linux-kernel - Re: + i386-time-avoid-pit-smp-lockups.patch added to -mm tree

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1161266225.11264.13.camel@c-67-180-230-165.hsd1.ca.comcast.net>
Date:	Thu, 19 Oct 2006 06:57:05 -0700
From:	Daniel Walker <dwalker@...sta.com>
To:	Andi Kleen <ak@...e.de>
Cc:	linux-kernel@...r.kernel.org, johnstul@...ibm.com, mingo@...e.hu,
	tglx@...utronix.de
Subject: Re: + i386-time-avoid-pit-smp-lockups.patch added to -mm tree

On Thu, 2006-10-19 at 15:47 +0200, Andi Kleen wrote:
> On Thursday 19 October 2006 15:44, Daniel Walker wrote:
> > On Wed, 2006-10-11 at 14:26 -0700, akpm@...l.org wrote:
> > 
> > > diff -puN arch/i386/kernel/i8253.c~i386-time-avoid-pit-smp-lockups arch/i386/kernel/i8253.c
> > > --- a/arch/i386/kernel/i8253.c~i386-time-avoid-pit-smp-lockups
> > > +++ a/arch/i386/kernel/i8253.c
> > > @@ -109,7 +109,7 @@ static struct clocksource clocksource_pi
> > >  
> > >  static int __init init_pit_clocksource(void)
> > >  {
> > > -	if (num_possible_cpus() > 4) /* PIT does not scale! */
> > > +	if (num_possible_cpus() > 1) /* PIT does not scale! */
> > >  		return 0;
> > >  
> > 
> > Can we ifdef some code here on CONFIG_SMP . It bugs me that there just
> > dead code laying around on smp systems.
> 
> The optimizer should optimize it all out since num_possible_cpus() is a 0
> constant on UP.

You just mean the if statement above though? I was talking more about
the structure above this called "clocksource_pit" which isn't used on
SMP systems due to this code addition. AFAIK init_pit_clocksource()
could disappear along with the clocksource structure ..

Daniel 

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/